Hearth panel apparatus for fireplace

ABSTRACT

A hearth panel includes an edge member defining a geometric shape, such as a continuous loop, and two (or more) non-combustible panels with perimeters contained inside the edge member, and with the panels defining an air gap therebetween, thus providing an R value of over 2.0 and as high as 3.5 or more. Spacers in the air gap help prevent drooping of the panels. Tile is attached to the top panel for aesthetics. In some versions, the edge member includes a flange forming the gap&#39;s thickness. In some versions, the edge member is roll formed from constant thickness sheet, or extruded from an extrudable material such as aluminum.

This application claims benefit under 35 USC section 119(e) ofprovisional application Ser. No. 62/035,026, filed Aug. 8, 2014,entitled HEARTHPAD, the entire contents of which are incorporated hereinin their entirety.

BACKGROUND OF THE INVENTION

The present invention relates to hearth panels such as are locatedunder, behind, and/or in front of fireplaces and heaters, and moreparticularly relates to a hearth panel apparatus having novelcost-competitive construction and high insulating R value.

Hearth panels have been manufactured for the fireplace industry sincethe late 1970's. They are used to protect combustible surfaces in homeshaving a wood stove, pellet stove, gas stove, and/or other fireplacestructure (collectively referred to herein as “heaters”), where thehearth panels provide a non-combustible surface for the heater to siton. Each brand and style of heater has specific requirements as to thelevel of floor protection and clearances to combustible surfaces,including both floors and walls near the heater/stove installation.

The hearth panel protects combustible surfaces from both radiant heatand possible sparks and embers that potentially could be released whenthe door of the heater is opened, or possibly if the glass in the dooris compromised. Certified labs have established standards for hearthpads to determine the level of protection they provide. Tests includethe R value of the hearth panel, impact tests, heat degradation testsand burning ember tests, as well as other tests.

In 2007, the industry divided hearth panels into type 1 and type 2categories. The type 1 hearth panel is required to provide spark andember protection. The type 2 hearth panel is required to provide sparkand ember protection, and must also provide thermal protection. Thehigher the R value, the greater the protection for combustible surfacessuch as carpet and wood floors. Today's market contains very efficientstoves with larger radiant heat output than in the past. This resultedin demand for greater radiant heat protection for hearth panels. Today,hearth panels must provide R values in excess of 2.5 if they are toprotect all radiant stoves currently in the marketplace. Hearth panelmanufacturers have not succeeded in designing and producing a singlehearth panel that singularly satisfies all wood stove models hearthprotection requirements. As a result, manufacturers of hearth panelsmust carry a variety of different hearth panel types in their inventory,which leads to increased manufacturing cost, inventory-in-process costs,and other costs associated with producing a wide variety of differentproducts at lower volumes.

It is a requirement that all wood burning stoves include in theirowner's manual a section addressing installation and all necessary floorand wall protection requirements. The owner of a newly purchased stoveor professional installer must consult the manual to determine adequatefloor protection and in some cases wall protection needed to insure asafe installation.

Presently, there are no hearth panels approved for R values thataccommodate all of these higher requirements. For example, several knownhearth panels have R values of only 1.40 to 1.60, which is well below anR value of 2.5. Yet there are at least 15 models of wood burning stovessold today with R value requirements that exceed 1.60.

To provide extra protection, some hearth panel manufacturers addsecondary products such as elevated platforms referred to as pedestalsthat include additional layers of non-combustible substrates. This addsadditional protection increasing the R values to satisfy theinstallation requirement of the specific heater. However, adding asecond product with another product to achieve satisfactory andacceptable protection has inherent problems. For example, it introducesopportunities for confusion by consumers, and misinformation from salespersonnel, about what products must be combined to provide a safe woodstove installation. Some consumers purchase a wood burning stove fromone source and a floor protector from a second source. This oftenresults in an error where inadequate hearth panel protection is matchedwith the wood stove heater. Any of these conditions can potentiallycause a fire in the consumer's home.

There are variations of type 2 hearth panel designs on the market.Numerous manufacturers of hearth pads have tested and approved designs.But none have accomplished a design that by itself protects combustiblesurfaces from all stoves offered on the market.

One hearth panel design has incorporated a steel angle iron (see FIG. 1)or aluminum edge (see FIG. 2) that supports a substrate. Tile, stone,granite or marble are added to the substrate surface for esthetics.There remains under the substrate an airspace that extends from thesubstrate to the existing combustible floor of the home. Aluminumsupports are added to the substrate to prevent sagging. Thismanufacturer obtains his elevation height for attaching his substrate byusing an angle iron style frame, adding narrow strips of the substrateand attaching that to the inside of the angle iron. Once the level isestablished, the substrate is attached to the buildup. This hearth paneldesign has no sealed internal airspace. The hearth panel relies on thesubstrate and the airspace under the substrate to achieve its thermalprotection. This hearth panel design has been in use since before 2007.This design has no internal airspace. This design provides a 1.6 Rvalue. (See FIG. 1.)

Another hearth panel design starts with an aluminum extruded edge thathas a horizontal flange approximately half way up the inside of theframe. A non-combustible substrate is attached to the frame. A secondnoncombustible substrate is attached to the bottom of the first layer.The bottom layer is smaller in width and length than the top layer andactually is positioned 3-4 inches away from the panel's edge along itsentire perimeter. The manufacturer refers on his web site to this designas follows: ½″ mineral fiber board installed to within inches of theframe. They go on to say “does not rely on air pocket for thermalvalue”. The combination of the two substrates achieves an R value of1.6. This design has been manufactured since 2008. (See FIG. 3.)

Another hearth panel design starts with an angle iron frame. The bottomhas a particle board attached to the frame. Then a noncombustiblesubstrate is attached to the top of the particle board. The estheticsurface material is attached by thin set to the noncombustiblesubstrate. The design has been used since 2009. This design provides a1.4 R value. (See FIG. 4).

There does not exist a universal solution for obtaining adequate Rvalues necessary for the newer high output radiant wood stoves usingonly one single hearth panel product. None offered for sale on themarket today exceed an R value of 1.6. This leaves several wood burningradiant stoves without a single complete-as-sold hearth panel productthat provides the safety needed for installations. Instead, a secondproduct must be used in conjunction with the hearth panel to satisfy therequired protection.

Besides the issue of inadequate R values, a second issue exists. Allknown manufactures use their edging material shapes to provide for a 90degree vertical edge. Esthetic materials (tiles etc.) are attached tothe panel surface and closely approach the outside vertical edge of thehearth panel. The ensuing gap that occurs between the edge and the tileis filled with grout. In many cases the tile or stone is installed veryclose to the panel edge leaving insufficient gaps to properly pack thevoid with grout. (See FIG. 3.)

This spacing gap produces a weakness in the product. Failures oftenoccur due to the following actions. Hearth panels are shipped tocustomers on pallets where fork lifts can damage this gap, installerscan drop the hearth panel on its edge during transportation, and thehome owner can damage this gap during regular use. Furthermore, thegrouted area as described above has a gap that can be compromised by theflex in the panel with the weight of the wood stove and with peoplestepping onto its edge. The result of these circumstances is hearthpanels with grout falling out of the gap.

Some known hearth panels are designed to provide airspace under thehearth panel (i.e. between the hearth panel and the building floor).However, when these are installed on carpet, the airspace is reducedsince the carpet tends to intrude into the airspace as it partiallycollapses under the weight of the wood stove or heater. Notably, woodstoves and heaters often exceed 100 pounds. Further, testing of suchhearth panel designs suggests they only provide R values of about 1.6,which is considerably less than the R value desired by many (if notmost) wood stoves and heaters.

An improvement is desired that provides savings/improvements in terms ofmaterial and assembly cost, capital investment, efficiency of install,and safety. Also, a universally-usable product is desired having an Rvalue sufficient high for use in all heaters, such as an R value of over2.0 and more preferably in excess of 2.50.

SUMMARY OF THE PRESENT INVENTION

In one aspect of the present invention, a hearth panel includes an edgemember defining a geometric shape; at least two non-combustible panelswith perimeters contained inside the edge member and that define an airgap therebetween; and spacers in the air gap preventing drooping of atop one of the non-combustible panels.

In a narrower aspect of the present invention, the edge member includesa flange that spaces at least two non-combustible panels apart, theflange having a thickness equal to the spacers.

In a narrower aspect of the present invention, the hearth panel includestile or stone on the top one of the non-combustible panels.

In another aspect of the present invention, a hearth panel includes anedge member having a cross section with a vertical flange and ahorizontal flange and connected to but spaced from the vertical flangeby a connecting flange; two non-combustible panels inboard of thevertical flange and located on or under the horizontal flange anddefining an air gap therebetween; and spacers in the air gap preventingdrooping of a top one of the panels.

In another aspect of the present invention, a hearth panel includes anedge member formed from a sheet having a constant width and constantthickness. The edge member has a cross section including a verticalflange and a horizontal flange. At least one non-combustible panelincludes a perimeter bounded by the vertical flange.

In another aspect of the present invention, an edge apparatus for ahearth panel is provided. The edge comprises a profile having a crosssection including a first edge portion that extends upwardly, a firstintermediate portion that extends outwardly and downwardly from a bottomof the first edge portion, a center portion that extends horizontallyinwardly from a bottom of the first intermediate portion, a secondintermediate portion that extends vertically upwardly from an inner edgeof the center portion, and a second edge portion that extendshorizontally inwardly from an upper edge of the second intermediateportion.

In a narrower form, the intermediate portion or the second edge portionhave two or more ribs increasing the air gap thickness defined by thecross section and by an insulative panel attached to and supported bythe profile.

In another aspect of the present invention, an edge for a hearth panelincludes an edge member formed from a sheet having a constant-thicknessand having a cross section including a first edge portion that extendsupwardly, a center portion that extends horizontally inwardly, and asecond edge portion that extends horizontally inwardly and that isspaced from the first edge portion. The edge member has a length lyingin a single plane and includes at least four linear sections each joinedby a sharp corner. Each sharp corner is formed by one of bending andwelding, where the corner formed by bending includes forming a notch atthe corner so that when bent the length stays in the single plane, andwhere the corner formed by welding includes cutting an angle on abuttingends so that when welded the length maintains the cross section to andaround the welded corner.

In another aspect of the present invention, an edge for a hearth panelis provided, where the edge comprises an edge member formed from a sheethaving a constant-thickness and having a cross section including a firstedge portion that extends upwardly, a center portion that extendshorizontally inwardly, and a second edge portion that extendshorizontally inwardly and that is spaced from the first edge portion.The edge member has a length lying in a single plane and includes atleast four linear sections each joined by a sharp corner, each sharpcorner is formed by a corner bracket connecting adjacent ends ofadjacent ones of the at least four linear sections.

These and other aspects, objects, and features of the present inventionwill be understood and appreciated by those skilled in the art uponstudying the following specification, claims, and appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1-4 are side views of existing prior art hearth panel designs,with FIG. 1A showing a front perspective view of one shape of suchdesigns.

FIGS. 5, 6, 6A, and 7 are side views of innovative hearth panels, FIG. 5showing a roll formed edge member and two (or more) MgO non-combustiblepanels spaced apart by an air gap, FIGS. 6-6A showing an edge member(roll formed or extruded) having a right-angle shape and two (or more)non-combustible panels spaced apart by an air gap, and FIG. 7 showing aextruded edge member with two (or more) non-combustible panels spacedapart by an air gap.

FIGS. 8-9-9A are cross sectional views of modified roll formed edgemembers for innovative hearth panels.

FIGS. 10-11 are cross sectional views using the modified roll formededge members of FIG. 9, with the FIGS. 10-11 being similar construction,but FIG. 11 showing use of a higher R value non-combustible substrate.

FIG. 12 is a cross sectional view using the modified roll formed edgemembers of FIG. 9, but using only a single non-combustible core layer incombination with hat channels steel supports supporting the core layerabove a floor space. Other spacer profiles may be chosen.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

The present innovation (referred to herein as “new design” or “ND”) is ahearth panel that incorporates a unique shape and construction to theedge which addresses the gaps issue described above.

The illustrated hearth panel 30 (FIG. 5) includes an edge member 31(roll formed, extruded, or otherwise formed), two (or more)non-combustible panels 32 and 33 with an air gap 34 therebetween, andtile 34 (e.g. slate, marble, sandstone, granite, or the like) attachedto a top of the panels 33 using grout or thinset or other adheringmaterial. Spacers 35 are placed in the air gap 34 inboard of the edgemember 31, with the spacers 35 having a thickness equal to the inboardflange of the edge member 31. The spacers 35 prevent drooping of a topof the panels 33, so that the air gap is consistently maintained andthus the R value maintained. The edge member 31 includes portions 40-44formed from a sheet having a constant-thickness and having a constantcross section. The constant profile includes a first edge portion 40that extends upwardly, a first intermediate portion 41 that extendsoutwardly and downwardly from a bottom of the first edge portion 40, acenter portion 42 that extends horizontally inwardly from a bottom ofthe first intermediate portion 41, a second intermediate portion 43 thatextends vertically upwardly from an inner edge of the center portion 42,and a second edge portion 44 that extends horizontally inwardly from anupper edge of the second intermediate portion 43. The first and secondedge portions 40 and 44 form an angle that is slightly greater than 90degrees, thus better allowing for grout as discussed below. The firstintermediate portion 41 is non-planar for aesthetics. The secondintermediate portion 43 is sufficient in length so that the bottomnon-combustible panel 32 fits under the second edge portion 44 and flaton a floor surface. Notably, the air gap can be any dimension desired,such as ⅛″ to ¼″ or more.

The versions shown in FIGS. 5-7 include similar components, features andcharacteristics. The same components, features and characteristics areidentified using the same numbers and/or using the same numbers but withletters or symbols (such as “A”, “B”, and/or using an apostrophe-') tosimplify the disclosure and reduce redundant discussion.

The ND (new design) discussion begins with the edge member (also calledan “edge” herein). Its shape is unique, and further the edge member canbe roll formed in a manner providing considerable savings in part cost,material cost, and providing high quality construction. Regarding theedge member, instead of a straight vertical surface, the edge tiltsoutwards creating additional gap spacing. This additional gap spacingallows for more grout to be applied into that space. This designstrengthens that portion of the hearth panel, reducing grout loss. (SeeFIG. 5.) As the edge descends further downward, the profile patternintroduces another feature that allows the side of the top layer of theMgO to come into contact with the edge. This contact prevents thin setand grout from falling down into the lower section of the profile. Ifthis was not designed into the shape, then hardened grout and thin setcould fall into that space, cure and harden, and rattle around.

Additionally, this profile feature provides for 2 right angle attachmentsites. These sites create an improved and more secure attachment. Theedge's descending profile comes into contact with the floor, returns tothe interior of the product, providing adequate support before ascendingupwards ½ inch. At ½″ the shape makes a 90 degree bend and travelsinward. This produces a flange parallel to the floor resulting inopposing right angles. (See FIG. 5.) Into each right angle of the edge,a ½″ sheet of MgO panel is attached. In some cases, the lower substratemay be a Micore 300, primarily used in place of the MgO product whenweight becomes a consideration. This creates a unique design whereas theproduct can accommodate 2 sheets of non-combustible substrates nowseparated by the flange creating a sealed internal airspace.

The present design allows for a variation on the composition of the corelayers. In addition to two layers of MgO ½″ substrates, a second optionis to substitute the bottom layer of MgO substrate with a layer ofMicore 300. It would also reduce the weight of the product.

In the illustrated design, three significant aspects thus create a muchhigher R value. It is noted that tile and thin set do not add very muchR value. The illustrated hearth panel includes two layers of MgO panels(or Micore 300) and a single internal airspace formed between the twosheets. Alternatively, a single layer of MgO substrate can be used incombination with a bottom layer of Micore 300. Notably, the bottom ofthe hearth panel sits fully flush to the floor. This concept is new and,to my knowledge, has never been sold in the marketplace. The projected Rvalue of the illustrated hearth panel is in excess of 2.0. Personsskilled in this art will understand that tested R values may vary fromprojected R values.

Thus, the ND creates unique features not used before in hearth paddesigns. The ND solves the gap problem that has occurred at a top ofmany existing hearth panels. The ND creates opposing right angles bywhich a duo layer of substrate can be installed securely to the edgewhile making full contact with that edge. Also, it provides for aninternal airspace layer. The internal airspace offers an R value of 0.50or more by itself, plus the air has no cost or weight, such that it isbelieved to be an important and strategic aspect of this innovation.

To summarize, the illustrated edge (see for example FIGS. 5-12) includesthe following advantages:

-   1. Vertical edge with outward bending profile allows for additional    grouting.-   2. Vertical edge with unique profile provides interior opposing    right angles for MgO, micore 300 and other substrates attachments    while maintaining exterior stylish profile.-   3. Internal horizontal flange creates secure attachment sites for    the substrates while providing an inherent internal airspace. The    width of the flange determines the thickness of the airspace. This    airspace will be ⅛″ or greater. A non-combustible spacer will be    placed in the center of the gap to prevent any sagging across the    airspace.-   4. The internal flange may be notched to allow for bending and    shaping at exacting locations.-   5. ND allows for internal welds connecting ends without disturbing    outside profiles.-   6. Flanges can be pre-drilled to allow screws to assist the adhesive    in attachment of the substrates to the right angles created by the    profile shape.-   7. The multiple bends and changing profiles of the edge add to the    strength of the form.-   8. The MgO product produces no off gassing.-   9. The MgO product combusts at temperature in excess of 3000 F.-   10. The MgO product carries Warnock Hersey stamp of quality.-   11. The MgO product is referred to by its trademark at MagBoard.    Over time other brands of MgO substrate may be used.-   12. The vertical edge with unique profile provides improved strength    due to the bends, while maintaining minimal wall thickness in the    extrusion, yet also allows control of air gap thickness, while again    allowing minimized wall thickness (e.g. FIG. 12).

Discussion of assembly: Steel coil is supplied to a roll form mill forproduction. The mill shapes the steel into a length necessary for eachhearth panel shape and size. During the process of shaping the coil, themill introduces pre-drilled holes as attachment sites for thesubstrates. Notches are placed in the vertical flange to facilitateaccurate and sharp bending specific corner locations to form the desiredshape.

The newly formed steel edge is placed in a fixture and bent using amandrel bender that prevents deformation of the profile and thatachieves accurate and precise shaping. Once the shape has been bent, theends are welded on the inside of the frame so as to not disturb theaesthetic profile. Each of the two layers of ½″ MgO panel are installedonto the frame with adhesives and screws. A non-combustible spacer iscentered between the two layers to prevent sagging and to support theintegrity of the internal air space. The edge and due corer panel isready for tile/stone/marble or granite to be attached to the top layerof the MgO substrate.

It is contemplated that variations could be made to the illustrated NDand still be within a scope of the present innovation. For example,there could be variations used to provide an internal airspace in ahearth panel besides the edge used in this particular ND design. A scopeof the present innovation is believed to include any use of an internalair space with a hearth panel, regardless of a particular technique orparticular construction used.

FIG. 6 illustrates a hearth panel 30A having an angle iron style edge,which edge could be extruded, roll formed, or bent on break die tooling.The edge is shaped to receive and for attachment of substrates. A planarpanel non-combustible substrate is installed to a bottom of the angleshape. Then spacers are introduced which are positioned along theperimeter, sitting on top of the bottom layer but along the perimeter inorder to provide for a second substrate installation. Then, a secondlayer of non-combustible substrate is attached to those spacers. Thisprovides an internal airspace. Tile or stone (or etc.) is then set onthe top layer of non-combustible substrate.

Notably, the edge can be extruded aluminum shapes, roll formed shapes,and/or shapes formed by other means. Design tooling could create woodproducts or plastic products that could establish a support flange onthe interior similar to FIG. 3 or 5. Then, using the support flange, twonon-combustible surfaces could be attached to the outside edge resultingin an interior enclosed airspace.

It is contemplated that a hearth panel using the present technology canincorporate additional layers of non-combustible sheet and spacers toform a second and possibly a third internally-enclosed airspace, thusachieving even higher R values. Alternatively, thinner layers ofsubstrate can be attached to the internal flange, producing an airspacebetween the existing floor and the hearth panel as well as the sealedinternal airspace.

FIGS. 6-6A illustrate hearth panels 30A and 30A′ incorporating an edgethat is extruded, roll formed, stock angle iron, wood, or plasticproduct shaped in an angle or channel form. The bottom substrate isattached to the edge. Spacers are placed around the perimeter sitting ontop of the bottom layer. Then, a second substrate is attached to thelayers. This creates an enclosed airspace, which is unlike previoushearth pads that used a C-channel or angle iron or other shape in theedge member. Tile is attached to the top layer. This pattern could berepeated various times to accomplish multiple sealed enclosed internalairspaces.

FIG. 7 illustrates a hearth panel 30B with an edge that is extruded,roll formed or shaped plastic or wood. The edge creates an internalflange. A substrate of lesser thickness is attached to the underside ofthe flange, leaving an airspace below the substrate. A second substrateis attached on top of the flange. This creates a second airspace. Tileis attached to the top layer of the substrate.

It is contemplated that hearth panel's edge member can be formed from asheet having a constant-thickness and having a cross section including afirst edge portion that extends upwardly, a center portion that extendshorizontally inwardly, and a second edge portion that extendshorizontally inwardly and that is spaced from the first edge portion.The edge member has a length lying in a single plane and includesmultiple linear sections each joined by a sharp corner. Notably, theedge member can form a continuous uninterrupted loop, such as a five orsix-sided loop often found in hearth panel shapes. Also, it iscontemplated that the edge member can leave off a rear linear section,such that it defines an open section (rather than a continuous loop).

It is contemplated that the hearth panel's edge member will havemultiple linear sections joined by sharp corners. The term “sharpcorners” is used herein to mean that adjacent linear sections are joinedby a portion of material that has minimal or zero radius. It issignificant that the sharp corner be formed so that the entire edgemember continues to lie in the single horizontal plane of its useposition. It is contemplated that the sharp corner can be formed byvarious means. For example, the sharp corners can formed by one ofbending and welding. Where the corner is formed by bending, the lengthis notched at the corner so that when bent, the length stays in thesingle plane (i.e. so that the material does not bulge upwardly ordownwardly when the sharp corner is bent). Where the corner formed bywelding, ends of the linear sections are cut at an angle on theirabutting ends so that, when welded, the welded length maintains thecross section to and around the welded corner. The angle cuts are usedto eliminate the need to overlap flanges at the sharp corners.

Also, instead of welding or bending, it is contemplated that the sharpcorners can be formed by using a corner bracket that both joinedadjacent abutting ends of linear sections and also that forms a sharp,aesthetic corner. The corner bracket would include short legs matching aprofile of the linear sections and attached to adjacent ends of thelinear sections, and a non-radiused section (or sharply radiusedsection) joining the short legs. Also, it is contemplated that acombination of bending and/or welding and/or brackets can be used.

It is noted that surface materials (previously referred to as “tiles”)are placed on top of the hearth apparatus, such as slate, marble,sandstone, granite, and other materials having an aesthetic appearanceand suitable non-flammable characteristics. They can be various shapesand sizes (i.e. various thickness and horizontal dimensions) and held inplace by various means, such as grout or cement.

FIG. 8 discloses a modified roll formed edge member 31 C for a hearthpanel. The edge member 31 C is modified to utilize steel having athickness that is reduced up to 0.06 inches from the edge members shownin FIGS. 5-7, such as to a thickness of about 0.06 inches (i.e. 1/16inch thickness). The edge member 31C includes portions 40C-44C, andadditionally includes a doubled-back portion 44C′ that maintains a gapthickness of ⅛ inch in the airspace. It is contemplated that a length ofthe doubled-back portion 44C′ can be as long or as short as a particulardesign or application requires. FIG. 8 shows another modified edgemember 30D with portions 40D-44D. Edge member 30D also uses 0.06 inchthick steel material, but instead of a doubled-back portion, the flange44D includes two (or more) ridges 44D″ so that a total defined thickness(i.e. a distance from a tip of the upward channels to a bottom surfaceof the flange 44D) is ⅛ inch thick. Thus, this flange 44D maintains theair gap thickness of ⅛ inch (0.06 inch). It is noted that variouspreferred dimensions of linear and radiused portions are included inFIGS. 8-9, but a scope of the present invention is considered to includemany variations as may be required for particular applications.

It is contemplated that the thinner steel of FIGS. 8-9 provides adequatestrength. Also, see the extruded edge of FIG. 9A with spacer ribs 44D″,and compare to the extruded edges of FIGS. 5 and 7 which can also usesimilar spacer ribs. The ribbed shape of edge 31D (FIG. 9) orfolded-back shape of edge 31C (FIG. 8) or ribbed extruded shape of edge31D′ with spacer ribs 44D″ (FIG. 9A, compare to FIGS. 5 and 7) maintainsthe ⅛″ (or more) internal air gap. The illustrated edge members providefor lower steel cost, lower tool cost, and lower part cost over thethicker parts of 0.1 inch thickness or thicker. Cut off dies cut the 45degree and 22-½ degree cut off necessary to accomplish the properabutting surfaces/shapes for welding corners so that the edge memberscombine to form a continuous loop or a partial loop in a hearth panelarrangement. The roll form tooling and the cut off dies constitute a twopart procedure to form the edge shapes and lengths needed for weldingparts together in the desired hearth shapes.

FIGS. 10-11 are cross sectional views using the modified edge members(roll formed or extruded) of FIG. 9, with the FIGS. 10-11 being similarconstruction, but FIG. 11 showing use of a higher R value at the lowernon-combustible substrate. Data on FIGS. 10-11 also provides details ofthe R values and dimension of the air space.

It is contemplated that the present edge member can be used in otherways. For example, FIG. 12 is a cross sectional view using the modifiededge member of FIG. 9, but using only a single non-combustible corelayer in combination with hat channels steel supports or other stylesupports supporting the core layer above a floor space. Data on FIG. 12also provides details of the R values and dimension of the air space.

It is noted that the edge member of FIG. 9 not only reduces materialcost, but also allows easier roll forming or extruding, thus leading toless expensive tooling, yet the double ribbed form on the horizontalflange provides for the ⅛ inch air space and can be increased to achievehigher R-values.

It is contemplated that the present innovative edge members (also call“profiles” herein) can be formed in ways other than roll forming. Forexample, a variant of the original edge member is made by extrudingprocesses while still utilizing the majority of the shape and conceptspreviously described. For example, an edge member like that shown inFIGS. 5-11 has been extruded from aluminum in given lengths that areconducive to cutting out parts for the hearth pad. The extrusion wasabout 0.06 inches in thickness with two ribs located on the interiorhorizontal flange, the two ribs defining an air gap when insulativepanels are supported by the extruded profile. It is conceivable thatother thickness of edge member materials could be used. It is alsoconceivable that more than two ribs could be formed into the flange anda thickness greater than ⅛″ could be implemented. Current testing forR-values produced a R-value of 2.0 utilizing the ⅛″ airspace, 1 layer of½″ MgO substrate and ½″ of micore 300 installed into the edge member. Byadding reflective foil like materials and with slight increases of theairspace higher R-values can be achieved. This patent would includeother insulative materials added to the airspace to increase R-values.

To form a hearth pad, the extruded aluminum edge member is placed in achop saw line to be cut into desired lengths, and those lengths areplaced into welding jigs to fix the pieces of aluminum in exact hearthconfigurations. Then the clamped pieces are welded internally to providea final shape and to preserve the outside profile and good cornerappearances. Any residue from the chop saw is sanded from the aluminumcorners, the edge member is then painted and ready for attachment of thesubstrates.

The ribbed attachment flange allows the use of ultra-thin aluminumextrusions while obtaining different airspace gaps for increasingR-values by simply increasing the size of the ribs on tools used toextrude the aluminum shape. The numerous shape changes in the profile ofthe edge member greatly increase the strength of the edge member. Thisallows for the use of ultra-thin aluminum edge members that both greatlyreduce the weight of the hearth pad, decreases the overall cost of thehearth pad yet provides for a structurally sound, esthetically pleasingand versatile hearth pad. Also, different rib sizes allow the designerto control a size of the air gap space and hence provide desired thermalproperties in the apparatus simply by changing a shape/configuration ofthe flange.

It is contemplated that the edge member could be produced from plastic,steel, aluminum and other materials (including even the use of wood) toachieve the same result. Over time substrates other than micore 300 andMagnesium Oxide panels may implemented in this hearth pad configurationthat will add positive features to this design.

Thus, it is to be understood that variations and modifications can bemade on the aforementioned structure without departing from the conceptsof the present invention, and further it is to be understood that suchconcepts are intended to be covered by the following claims unless theseclaims by their language expressly state otherwise.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. A hearth panelcomprising: an edge member defining a geometric shape; at least twonon-combustible panels with perimeters contained inside the edge memberand that define an air gap therebetween; and spacers in the air gappreventing drooping of a top one of the non-combustible panels.
 2. Thehearth panel of claim 1, wherein the edge member includes a flange thatspaces the at least two non-combustible panels apart, the flange havinga thickness equal to the spacers.
 3. The hearth panel of claim 2,wherein edge member has an exterior surface that is non-planar andaesthetically shaped.
 4. The hearth panel of claim 1, including one oftile or stone on the top one of the non-combustible panels.
 5. Thehearth panel of claim 1, wherein the geometric shape defines acontinuous loop lying in a horizontal plane when in a use position. 6.The hearth panel of claim 1, including an additional non-combustiblepanel forming an additional air gap with the first-mentionednon-combustible panels.
 7. A hearth panel comprising: an edge memberhaving a cross section with a vertical flange and a horizontal flange;two non-combustible panels inboard of the vertical flange and located onor under the horizontal flange and defining an air gap therebetween; andspacers in the air gap preventing drooping of a top one of the panels.8. A hearth panel comprising: an edge member formed from a sheet havinga constant width, the edge member having a cross section including avertical flange and a horizontal flange connected to but spaced from thevertical flange by a connecting flange; and at least one non-combustiblepanel with a perimeter bounded by the vertical flange.
 9. The hearthpanel of claim 8, wherein the horizontal flange is notched at corners tofacilitate forming the corners while preventing deformation when formingthe corners.
 10. An edge apparatus for a hearth panel, the edgecomprising: a profile formed from a sheet having a cross sectionincluding a first edge portion that extends upwardly, a firstintermediate portion that extends outwardly and downwardly from a bottomof the first edge portion, a center portion that extends horizontallyinwardly from a bottom of the first intermediate portion, a secondintermediate portion that extends vertically upwardly from an inner edgeof the center portion, and a second edge portion that extendshorizontally inwardly from an upper edge of the second intermediateportion.
 11. The edge apparatus defined in claim 10, wherein the firstintermediate portion extends outwardly and downwardly at an angle. 12.The edge apparatus defined in claim 10, wherein the first and secondedge portions do not touch each other but form an angle that is 90 to 95degrees.
 13. The edge defined in claim 10, wherein at least one of theintermediate portion and second edge portion have two or more ribsincreasing an air gap defined by the cross section and by an insultativepanel attached to and supported by the profile.
 14. An edge for a hearthpanel, the edge comprising: an edge member formed from a sheet having aconstant-thickness and having a cross section including a first edgeportion that extends upwardly, a center portion that extendshorizontally inwardly, and a second edge portion that extendshorizontally inwardly and that is spaced from the first edge portion;the edge member having a length lying in a single plane and including atleast four linear sections each joined by a sharp corner, each sharpcorner being formed by one of bending and welding, where the cornerformed by bending includes forming a notch at the corner so that whenbent the length stays in the single plane, and where the corner formedby welding includes cutting an angle on abutting ends so that whenwelded the length maintains the cross section to and around the weldedcorner.
 15. An edge for a hearth panel, the edge comprising: an edgemember formed from a sheet having a constant-thickness and having across section including a first edge portion that extends upwardly, acenter portion that extends horizontally inwardly, and a second edgeportion that extends horizontally inwardly and that is spaced from thefirst edge portion; the edge member having a length lying in a singleplane and including at least four linear sections each joined by a sharpcorner, each sharp corner is formed by a corner bracket connectingadjacent ends of adjacent ones of the at least four linear sections.